Suction cleaning device



July 25, 1961 D. c. KRAMMES 2,993,223

SUCTION CLEANING DEVICE Filed June 19, 1959 3 Sheets-Sheet 2 Fig.3

Fig. 2

July 25, 1961 D, c, KRAMMES 2,993,223

SUCTION CLEANING DEVICE Fi1 ed June 19, 1959 a Sheets-Sheet 3 *f *N 1 II I 1 t 2 United States Patent 2,993,223 SUCTION C EANING DEVICE Don C.Krammes, Canton, Ohio, assignor to The Hoover Company, 'Canton, Ohio, acorporation of Ohio Filed June 19, 1959, Ser. No. 821,454 6 Claims. (Cl.15-320) The present invention relates to a suction cleaning device andmore particularly to means for inhibiting or suppressing the formationof suds or foam in a unitary floor scrubber having all of the necessaryadjuncts for dispensinga clean detergent solution onto a floor or othersurface to be scrubbed, for scrubbing the detergent over the floor todissolve and loosen the dirt and grime thereon and then to dry the floorby removing the dirty detergent solution from the floor by means of asuction air stream.

In its broader sense the present invention relates to inhibiting foam orsuds in a moving air stream which carries a liquid having a tendency toform foam or suds. According to the invention, that is done by means ofa defoamant cake having an active defoaming agent dispersed throughout anormally solid carrier which is soluble in the liquid to be treated. Thedefoamant cake is placed in the moving wet air stream so that the liquidcontacts the cake and slowly dissolves the carrier to slowly release thedefoaming agent into the air stream and thus into contact with theliquid to be treated to inhibit the formation of foam or to suppressfoam already formed.

The invention is disclosed herein as applied to a suction scrubbingapparatus which includes a scrubbing suction nozzle, a storage tank forclean detergent solution, means for dispensing the detergent solution tothe nozzle, a motor-fan unit for drawing a suction on the nozzle to pickup the dirty detergent solution after the scrubbing operation, aseparator for separating the dirty detergent solution from the suctionair stream and a. tank for receiving the dirty detergent solution fromthe separator. In the machine of the present invention, the motor-fanunit is intended to be in operation at all times during operation of themachine. The suction passage of the machine is vented to atmosphere andclean detergent solution dispensed onto the floor through the suctionnozzle and spread around over the floor by moving the machine about asthe liquid detergent is dispensed. With the suction passage still ventedto atmosphere, the detergent solution is then scrubbed about over thefloor by means of the bristled suction nozzle, to loosen dirt and grimefrom the floor. If the floor has been waxed some of the waxmay also beremoved. The vent in the suction passage is then closed to cause suctionto be applied at the suction nozzle whereby the dirty detergent solutionis sucked up by the suction nozzle and carried by the suction air streaminto the separator.

In thus scrubbing certain waxed floors, by the use of certaindetergents, suds and foam tend to form in great volume which adverselyaffects the operation of the machine in an obvious manner.

It is an object of the present invention to prevent the formation ofsuch foam regardless of the wax or soap combination present during thescrubbing operation.

According to the present invention, the previously described defoamantcake is placed in the detergent laden suction air, stream at any pointbefore it reaches the separator. According to the preferred form of theinvention the defoamant cake is placed in the suction nozzle where itwill be contacted by the dirty detergent solution carried by the suctionair stream during the suction pick up or drying operation, long beforeitreaches the separator. z

However, according to the broader aspects of the invention, thedefoamant cake may be placed at any point in the suction air streamwhere it will be contacted by the dirty detergent solution carried bythe air stream. Also, according 'to the invention, the defoamant cakemay be positioned in any moving air stream which carries a potentiallyfoaming liquid or a liquid in which a foam has already formed.

Other objects and advantages of the present invention will becomeapparent as the description proceeds when taken in connection with theaccompanying drawings in which:

FIG. 1 is a perspective view of the appliance of the present inventionwith the detergent tank removed,

FIG. 2 shows the suction nozzle of the machine of the present inventionpartly broken away to show how the defoamant cake is positioned,

FIG. 3 is a sectional view of the nozzle of FIG. 2 taken on line 33thereof,

FIG. 4 is a plan view of the top of the water separator, partly brokenaway, to show how a defoamant cake, according to a modification of theinvention, is mounted,

FIG. 5 is a sectional view of the modification of FIG. 4 taken on line5-5 thereof and,

FIG. 6 is a segmental sectional view taken on line 6-6 of FIG. 4.

Referring to FIG. 1 of the drawings, the scrubbing machine of thepresent invention includes a combined scrubber and suction nozzle 10, amotor-fan unit 11, a combined clean and dirty detergent tank 12, aliquid separator 13 and a propelling handle 14.

The nozzle 10 includes two rows of spaced apart bristles 15 which aresecured to a bottom plate 16 (FIG. 3) having a narrow suction slit 17.The bristles 15 are relatively still? and in effect form the suctionmouth for the nozzle 10.

The suction tube 18 (FIG. 3) is detachably connected to the extension 19of the nozzle by a well known bayonet connection by which the nozzle 10may be removed by rotating it 180 and moving it axially of the tube 18.

The suction tube 18 extends through the split motor housing 20 and itsupper end is connected to the wet suction tube 21. The manner in whichthat is done and the manner by which the suction circuit, including theseparator 13, is connected to the suction side of the motorfan unit ismore clearly shown by my co-pending application Serial No. 754,093 filedAugust 8, 1958.

The tube 21 communicates with the upper left hand side of the separator13 and the dry suction tube 22 connects the upper right hand side of theseparator 13 to the suction side of the motor-fan unit 11, all as shownby my aforementioned application Serial No. 754,093. The interiorconstruction of the separator is also shown in that application. I p

The tank 12 is clamped between the upper end ofthe motor-fanunit 1'1 andthe lower end of the separator 13.

collected occupies the space in tank 12 formerly occupied. by the cleandetergent. The arrangement is shown in my copending application SerialNo. 652,565 filed April 12,

The bottom 24 of the tank 12 is provided with a valved opening normallyclosed by a spring valve 25 having an extension 26 adapted to becontacted by a control rod 27 actuated by a control lever 28 at the topof handle 14. The lid 29 for the separator 13 is pivoted to theseparator 13 at its rear end. It is opened and closed by the controllever 28. The manner by which the control lever operates to open valve25 and to open and close lid 29 is more fully disclosed by my copendingapplication Serial No. 753,900 filed August 8, 1958.

The machine is supplied by electric current by an electric cord 30connected to the switch 31 and to the motor-fan unit 11 in any mannerknown to the art.

The handle 14 houses the control rod and the electric cord 30. Itextends downwardly through a bore in the rear of the separator 13 andforms a support for that vessel. At its lower end the handle 14 isrigidly attached to the motor-fan unit and in eifect forms thesupporting backbone for the entire apparatus.

As shown by FIG. 3, the interior central portion of the nozzle isdivided into a plurality of compartments by downwardly extending spacedapart fingers 32 which form a support for a defoamant cake 33 whichrests upon the bottom plate 16 in the front central portion of thenozzle 10.

- The cake 33 may be inserted into the pocket 34 through an opening inthe top of the nozzle 10 which is normally closed by a removable closureor lid 35 which is preferably made of flexible plastic material so as toform a good seal about the edges of the opening in the nozzle 10.

At its rear end the lid 35 is provided with a downwardly extending rib36 which fits in a groove 37 formed in the top wall of nozzle 10.Forwardly of the rib 36 the lid 35 is formed with a plurality of lockingtabs 38 having hooked ends 39 which fit between the spaced fingers 32 tohold the rear end of lid 35 in place. Adjacent its forward edge, the lid35 is formed with a plurality of downwardly extending locking tabs 40which fit beneath a ledge 41 of the top wall of nozzle 16. Forwardly ofthe tabs 40 the lid 35 is formed with a downwardly extending rib 42which fits closely against the front wall of the nozzle 10 as shown inFIG. 3. The rib 42 serves as a hand hold for removing the lid 35 andalso extends along the ends of lid 35 to fit into grooves 43 formed inthe top wall of the nozzle 10 as shown by FIG. 2.. v To apply the lid35, its rear end is pressed downwardly to push the rib 36 into thegroove 37 and to position the hooked ends 39 of tabs 38 in the spacebetween fingers 32 which locks the rear end of the lid in place. Thefront end of the lid 35 is then pressed downwardly which snaps the tabs40 beneath the ledge 41 to lock the lid 35 in place and form a sealabout its entire periphery. That operation is easily accomplished sincethe lid 35 is flexible. To remove the lid it is merely necessary to liftup on the rib 42 to release the tabs 40 from beneath the ledge 41 and tothen sort of pivot or rotate the lid upwardly and rearwardly.

The defoamant cake 33 is in a stable normally solid form and comprisesan active defoaming agent preferably a liquid silicone dispersed in awater soluble carrier preferably a water soluble wax. An emulsifyingagent for the silicone is also preferably dispersed in the wax alongwith the silicone so as to be in contact therewith.

The soluble wax is slowly dissolved or eroded away upon contact withwater so as to expose the silicone and emulsifier whereupon the siliconethus exposed immediately forms an emulsion with the water to thusrelease the active defoaming agent.

It is to be noted from FIG. 3 that the defoamant cake 33 is positionedabove and adjacent to the suction slit 17 and that the fingers 32 arepositioned to the rear of the slit 17. Thus as liquid and air are drawnupwardly at a comparatively high velocity, the liquid will be splashedabout and come into contact with the defoamant cake 33. p

4 Operation of FIGS. 1-3

The motor-fan unit 11 is energized by actuation of the switch 31. Thecontrol lever 28 is then actuated to open lid 29 and vent the suctionline and to open the valve 25 and dispense clean detergent solution ontothe floor. The detergent solution may be spread about by moving themachine about and spreading the solution by means of the bristles 15.

The control lever 28 is then actuated to close valve 25 while the lid 29remains open so that no suction will be applied at the nozzle 10. Themachine is then vigoroulsly moved about and the bristles 15 applied tothe floor to scrub the detergent solution about to loosen dirt and grimeand dissolve it into the solution.

After the floor is thoroughly scrubbed the'control lever 28 is actuatedto close the lid 29 so that the suction of the motor-fan unit is appliedat the nozzle 10. The bristles 15 will form a narrow suction mouth andthe dirty solution will be drawn beneath the lower ends of the bristles15 and through the end openings. The suction applied to the area betweenthe two rows of bristles will lift the dirty solution from the fioorinto the suction air stream.

As the mixed air and dirty detergent solution passes through the suctionslit 17 its velocity will be increased and it will be projected upwardlyinto the interior of the nozzle 10. The machine of the presentinvention, under such conditions, handles 18 cubic feet of air 'perminute and will normally pick up from to cc. of dirty solution perminute.

The detergent solution is a solution of soap in water which tends toform foam and suds. As the mixture of detergent, air and water isprojected through the suction slit 17 it isv splashed about and thewater comes into contact with the defoamant cake 33 and slowly dissolvesor erodes away the soluble wax carrier to expose the active defoamingagent in contact with the emulsifier which immediately forms an emulsionof the silicone with the water and suppresses any foam present orinhibits the formation of foam if none is present.

After leaving the nozzle 10, the mixture of air, water, soap andemulsified defoamer passes through suction tube 18, the wet suction tube21, the separator 13 and the dry suction tube 22 to the eye of themotor-fan unit 11. In the separator 13 the dirty detergent solution isseparated from the suction air stream and drips through opening 4,4-into the dirty detergent bag in the top of tank 12. Should the suctionair stream contain foam or suds as it enters the separator 13 it wouldsoon render that vessel inoperative and at least a portion of the dirtydetergent solution would be carried over to the motorfan unit 11 andeventually flow back onto the floor.

That is prevented by the action of the defoamant cake in suppressingfoam already formed and in inhibiting the potential formation of foam inthe suction air stream.

When the defoaming effectiveness of the defoamant cake has beensubstantially reduced it is replaced by another similar defoamant cakeas explained above.

It is to be understood that it is not essential that the components ofthe defoamant cake be those above described but that any activedefoamant may be used dispersed in a water soluble carrier. Thedefoamant described above is one that has been found to be veryeffective and long lived in the machine according to the presentinvention.

FIGS. 4 to 6 disclose a modification of the invention applied to thesame general type of machine as that of the first modification but inwhich the defoamant cake is positioned in the suction air stream at apoint just-before it enters the separation chamber of the separator 13.

As shown by FIG. 5 the wet suction tube 21 communicates with theinterior of the separator 13 by means of an inlet passage 45 in the sidewall of the separator 13. Immediately abovethe opening 45 is a pocket 46for receiving a defoamant cake 47. The walls forming the bottom ofpocket 46 are provided with numerous openings 48 through which waterfrom the suction air stream is projected before it enters the interiorproper of the separator 13.

The pocket 46 is provided with an access opening 49 closed by a door 50having a sealing member 51 which seals the interior of pocket 46 againstair leakage when the door 50 is closed.

The door 50 is located beneath the separator lid 29 and the pad 51 isheld in sealing engagement with the edges of opening 49 by the pin 52pressing downwardly on lid 50 when the separator lid 29 is closed duringthe suction pick-up periods, which is the only time a seal need beprovided.

The lid 50 may be raised for the replacement of the defoamant cake 47 byfirst opening the separator lid 29 and then removing the lid 50.

Operation of FIGS. 4-6

The operation of the machine is carried out in the same manner asbefore. As the mixture of air, water and detergent leaves the upper endof pipe 21 it is moving at quite a high velocity and the water anddeter-gent droplets are impinged against the bottom wall of the pocket46 and some of the water droplets will pass through the openings 48 intocontact with the defoamant cake 47 and slowly dissolve or erode it torelease the active defoaming agent into contact with the water tosuppress any foam already present and to inhibit foaming in theseparator 13.

From the foregoing it can be seen that the present invention provides asimple and inexpensive way by which foaming and suds forming in an airstream carrying a liquid having an inherently foaming characteristic maybe suppressed and/ or inhibited.

It can also be seen that the present invention provides a scrubber andsuction pick-up drier having a suction air stream carrying a mixture ofair, detergent and water with a simple way by which any foam formed willbe suppressed and any incipient tendency for foam to form will beinhibited.

While I have shown and described but two embodiments of my invention itis to be understood that those embodiments are to be taken asillustrative only and not in a limiting sense. I do not wish to belimited to the particular structure shown and described but wish toinclude all equivalent variations thereof except as limited by the scopeof the claims.

I claim:

1. A detergent solution pick-up appliance comprising, a suction nozzle,suction creating means, means forming a suction flow path between saidnozzle and said suction creating means, said suction nozzle being formedto pick up detergent solution in the air stream flowing therethroughwhereby a mixture of air and detergent solution enters said air flowpath through said nozzles, a liquid separator in said suction -flow pathfor removing said detergent from said mixture, and a foam inhibiter insaid air flow path ahead of said separator and positioned for contactwith said mixture, said inhibiter being in the form of a body includingan active defoaming agent dispersed in a normally solid water solublecarrier whereby said active defoaming agent is released as said mixturecontacts said body to dissolve said carrier.

2. An appliance according to claim 1 in which said foam inhibiter bodyis positioned in said air flow path where said mixture is flowing at ahigh velocity so as to impinge against said body to aid in the releaseof said active defoamant.

3. An appliance according to claim 1 in which said body is positioned insaid nozzle immediately above its entrance in a position to be contactedby said mixture as it enters said nozzle.

4. An appliance according to claim 3 in which said body is positioned ina pocket in said nozzle and a removable closure for said pocket forready access to said body.

5. An appliance according to claim 1 in which said body is positioned insaid air flow path at the entrance to said separator.

6. An appliance according to claim 5 including a receiving pocket formedin the wall of said separator in which said body is positioned forcontact with said mixture before it enters said separator and aremovable closure for said pocket for ready access to said body.

References Cited in the file of this patent UNITED STATES PATENTS1,440,026 Nilsson Dec. 26, 1922 2,407,408 Erickson Sept. 10, 19462,649,758 Cowgill Aug. 25, 1953 2,673,619 Martin Mar. 30, 1954 2,763,880Brown Sept. 25, :1956 2,923,956 Bixler Feb. 9, 1960 2,953,159 Geschka etal. Sept. 20, 1960

